Sheet feeding system



Aug. 7, 1962 Filed Sept. 4, 1959 R. S. BRADSHAW ET AL SHEET FEEDING SYSTEM 8 Sheets-Sheet 1 IN VEN TORS.

ROBERT S. BRADSHAW ROLAND LESSIG ATTORNEY Aug. 7, 1962 Filed Sept. 4, 1959 R. s. BRADSHAW ETAL 3,048,394

SHEET FEEDING SYSTEM 8 Sheets-Sheet 2 INVENTORS. ROBERT S. BRADSHAW ROLAND LESSIG ATTORNEY Aug. 7., 196 R. s. BRADSHAW ET AL SHEET FEEDING SYSTEM 8 Sheets-Sheet 3 Filed Sept. 4, 1959 ATTORNEY INVENTORS. ROBERT S. BRADSHAW ROLAND LESSIG 1962 R. s. BRADSHAW ET AL 3,048,394

SHEET FEEDING SYSTEM 8 Sheets-Sheet 4 Filed Sept. 4, 1959 HVVENTDRS. ROBERT S.BRADSHAW BY ROLAND LESSW ATTORNEY 7,, 1962 R. s. BRADSHAW ETAL 3,048,394

SHEET FEEDING SYSTEM 8 Sheets-Sheet 5 Filed Sept. 4, 1959 INVENTORS. ROBERT S. BRADSHAW ROLAND LESSIG ATTORNEY 1962 R. s. BRADSHAW ETAL 3,048,394

SHEET FEEDING SYSTEM Filed Sept. 4, 1959 8 Sheets-Sheet 6 BY Mm ATTOR NEY 1962 R. s. BRADSHAW ETAL 3,048,394

SHEET FEEDING SYSTEM 8 Sheets-Sheet 7 Filed Sept. 4, 1959 III'IIIIIJ" v w 815* wIIIIIIII/IIIIIA INVENTORS. ROBERT S. BRADSHAW ROLAND LESSIG AT TORN E d d F Aug. 7, 1962 R. s. BRADSHAW ET AL 3,048,394

SHEET FEEDING SYSTEM Filed Sept. 4, 1959 8 Sheets-Sheet 8 INVENTORS.

ROBERT S. BRAD HAw ROLAND LESSIG ATTORNEY m m mm wv Q A w mm mm m E ow Om MVN LI fl\ 6 mm mm as J mm on m V\ m \|1\ Ev ww 9 United States Patent 3,048,394 SHEET FEEDING SYSTEM Robert S. Bradshaw, Broornall, and Roland Lessig, Philadelphia, Pa, assignors to Burroughs (Jorporation, Detroit, Mich, a corporation of Michigan Filed Sept. 4, 1959, Ser. No. 838,324 11 Claims. (Cl. 27162) This invention relates generally to sheet feeding systerns and more particularly to such a system including novel apparatus for moving a stack or pile of sheet items to a sheet feeding device where the Sheets are separated individually and sucessively from the stack. While the invention is useful in a variety of applications in the sheet feeding art, it finds special application in bank bookkeeping machines and the like for processing a stack of forms or documents, such as ledger account record cards or sheets, and therefore it will be described hereinafter in connection with such use.

The primary object of the invention is to provide an improved system for feeding a stack or pile of sheets from one place to another, one sheet at a time sequentially.

Another object of the invention is to provide such a system which will automatically maintain the top or end sheet of a stack or pile of sheets at a predetermined substantially constant feeding position or level adjacent to a feeding device as sheets are fed successively and individually from the stack by the device.

A further object of the invention is to provide a sheet feeding system wherein a removable container or magazine for holding a supply of sheet items, is moved to and from a sheet feeding device as controlled by instrumentalities making the operation substantially automatic and preventing operation in the event the container is not properly positioned in the apparatus.

A still further object of the invention is to provide a sheet stack moving mechanism having a quick-return drive means whereby the sheet stack may be moved to the feeding device at one speed and quickly returned to its starting or loading position at a faster speed and stopped without shock to the mechanism.

In accordance with the above objects and considered first in its broad aspects, the invention comprises a sheet feeding system including apparatus for supporting and moving a stack of sheet items to and from a sheet feeding device, and in which control instrumentalities are incorporated to make the system substantially automatic to move the sheet stack from a loading station to a predetermined feeding position where the sheets are separated individually and successively from the top or end of the stack and fed to a receiving station until all the sheets are removed from the stack, and then return the supporting apparatus rapidly to its loading station.

The invention will be more fully revealed in the following detailed description of the preferred embodiment thereof when read in conjunction with the accompanying drawings in which:

FIG. 1 is a perspective view looking at the right side of a bank bookkeeping machine utilizing a sheet feeding system in accordance with the present invention;

FIG. 2 is a front perspective view of the machine of FIG. 1;

FIG. 3 is a right side elevational view of the machine;

FIG. 4 is a fragmentary sectional view illustrating a supply magazine and a stacking magazine positioned in the machine and in line with track portions of a loading platform of the machine, the supply magazine being in starting or loading position and supported in the elevating mechanism of the invention;

FIG. 5 is an enlarged sectional view taken along line 5-5 of FIG. 4;

3,048,394 Patented Aug. 7, 1962 ice FIG. 6 is a view taken along line 66 of FIG. 4;

FIG. 7 is a sectional view taken along line 7-7 of FIG. 6;

FIG. 8 is a sectional view taken along 8-8 of FIG. 6;

FIG. 9 is a sectional view of a fragmentary portion of a magazine partition member taken along line 9--9 of FIG. 12;

FIG. 10 is a perspective view of a magazine adapted to be used interchangeably in the supply and stacking stations;

FIG. 11 is a schematic diagram of a control circuit;

FIG. 12 is another view of a magazine with parts broken away to more clearly reveal other parts;

FIG. 13 is a sectional view taken along line 1313 of FIG. 12;

FIG. 14 is a sectional view of a two-speed reversing drive mechanism taken along line 1414 of FIG. 6;

FIG. 15 is a view taken along line 15-15 of FIG. 4 and showing a portion of the stacking magazine and partially broken away to reveal other parts;

FIG. 16 is a sectional view taken along line 1616 of FIG. 15; and

FIG. 17 is a sectional view taken along line 17--17 of FIG. 15 and illustrating a switch for conditioning the circuit for operation of a valve for supplying vacuum to a sheet feeding device.

The specific or preferred form of the invention disclosed is specially designed for use in, but not limited to, the bank bookkeeping machine described and claimed in a co-pending application of Robert S. Bradshaw, Serial No. 830,391, filed August 29, 1959, with the title Sheet Handling Apparatus and assigned to the assignee of the present invention.

The machine as described in the Bradshaw application, and as illustrated in FIGS. 1 to 3 of the present application, comprises an enclosure or cabinet 1 which is rectangularly shaped, a control unit 2 adjacent the front of the cabinet, and a magazine loading platform 3 adjacent the right-hand side wall 4 of the cabinet. The cabinet includes a principal or main sheet supply or loading station 5 from which record items such as ledger sheets are individually and successively fed into a main or primary document feeding path 6 and advanced therethrough to the stacking station 7. As is evident in these figures, the supply and feeding stations are located in the lower portion of the cabinet.

Whenever it is desired to withdraw a ledger from the normal or primary feeding path for the attention of the operator, an auxiliary or secondary delivery path 8, shown at the top of FIG. 3, is coupled with the primary feeding path 6 by suitable switching means (not shown) to deflect the selected sheet into the auxiliary delivery path for feeding therealong into an auxiliary stacking bin 8a preferably located at the front end of the machine for easy accessibility.

Occasionally it is necessary to insert a ledger sheet into the primary feeding path 6 from another source and this is provided by a manual insertion slot 9 and an automatic insertion slot 9a.

During its movement around primary path 6 certain operations may be performed on the ledger sheetssuch as printing and magnetic recordingand these are more specifically described in the above-mentioned Bradshaw application, but they are not important to an understanding of the present invention, now to be described, and therefore a description of these features has been omitted here.

Now referring more particularly to FIGS. 6, 8 and 14, it will be seen that the preferred form of the invention comprises an elevating mechanism for moving a ledger supply magazine or container at one speed from its loading station to a feeding station where the ledgers are separated one at a time from the stack and into the primary feed path, through which they are transported to a stacking magazine and for returning the container to its loading station at another speed. To this end the apparatus includes a two-speed reversible drive mechanism 10 for advancing a supply or stack of sheet items such as ledger cards or sheets 12 to a sheet feeding device 14 (FIG. 8) which is adapted to separate the sheets individually and successively from the stack and feed them into the primary path 6. The sheet feeding device 14 may be of any well known construction but is preferably of the vacuum wheel type of the class shown in the United States Patent No. 939,260.

The elevating mechanism is supported on a stationary framework of the machine including inclined supporting members 16 and 18 (FIGS. 6 and 8) and spaced cross members 20 and 22 secured to members 16 and 18. An elevating screw 24 is journalled for rotation at its end portions in cross members 20 and 22, and has secured on its lower end portion coaxial driven bevel gears 26 and 28 (FIG. 14). A drive shaft 30' is journalled in anti-friction bearings in bearing brackets 32 and 34 secured to cross member 22, and has secured on its outer end (FIG. 6) a pulley 36 coupled to a motor M by means of a belt 38. Secured to the bearing brackets 32 and 34 are solenoids 40 and 42 respectively of electromagnetic clutches 44 and 46. The electromagnetic clutch 46 includes a magnetizable driving disc 48 secured to the drive shaft 30, as by set screw '49, and a driven armature disc 50 slidably keyed on a splined bushing 52. The bushing 52 is secured to a bearing 54 freely rota-table on the drive shaft 30 and to a sleeve 56 secured to a bevel driving gear 58 and a bearing 60 freely rotatable on the drive shaft. The electromagnetic clutch 44 includes a magnetizable driving disc 62 secured to the drive shaft 30, and a driven armature disc 64 slidably keyed on a splined bushing 66. The bushing 66 is secured in a bevel driving gear 68 and on a bearing 70 freely rotatable on the drive shaft 30.

The elevating screw 24 (FIG. 8) is threadedly engaged in a nut 72 secured to the underside of the forward member 74 of a Vshaped or trough-like cradle 76, whereby the rotative movement of screw 24 is translated into linear movement of the cradle. The rearward member 78 of the cradle 76 is provided with spaced rectangular apertures 80 (FIG. through which extend projections 82 of a fixed stop bar 84 when the cradle 76 is in its lowermost or loading position. The forward member 74 of the cradle 76 is provided at its top edge, as seen in FIG. 6, with an upwardly extending stop flange 86 to which is secured a cam 88 for operating a lower limit switch 90 (see also FIG. 11). Also secured to the under side of the forward member 74 of the cradle 76 are bearing blocks 91 slidably mounted on shafts or ways 92 and 94 secured at their end portions to the cross members 20 and 22 thus to support and guide the cradle 76 during its movements to and from the feeding device 14.

A container or magazine 96 (FIGS. and 12) for containing the sheets 12 is adapted to be used interchangeably either as a supply magazine 96a, as shown in FIG. 8, and as shown in the forward or left-hand position in FIG. 4, or as a stacking magazine 96b as shown in the rearward or right hand position in the same figure. The container or magazine 96 will shortly be described in detail in connection with the present invention, but first it is to be noted that the magazine is the subject of a separate invention not claimed herein but fully described and claimed in a coapending application of John G. Smith, Serial No. 838,501, filed September 8, 1959, entitled Magazine for Holding Sheets, and assigned to the same assignee as the present invention.

The magazine is of box-like construction and comprises left and right slotted side walls 98 and 100 respectively, front and rear end walls 102 and 104 respectively, and a bottom wall 106. The under side of the bottom wall 106 (FIG. 10) is faced around its marginal portions with strip 108 of a low friction material such as nylon, for example, to facilitate sliding the magazine into and out of the apparatus. The front and rear walls 102 and 104 are fitted with hearing strips 110 of a similar material. The front wall 102 is provided with an indentation or cut-out 112 for freely admitting the vacuum feed wheel 14 and a normally closed sensing switch 114 (FIGS. 8 and 11) to the top of the stack of cards during the course of operation, as will be explained.

The magazine 96 (FIG. 12) is provided in its interior with a movable partition 116 which is manually set to adjust the size of the sheet containing compartment 118 to the particular thickness or height of the stack of sheets 12 when the magazine is used as a supply magazine. When the magazine is used as a stacking magazine, as will be described more fully hereinafter, the partition is latched against the rear wall 104 (FIG. 10) on an anchor post 120 secured to the rear wall.

The partition 116 comprises an outer shell of closed box-like construction preferably formed of sheet metal and having an aperture 122 in its upper horizontal wall 124 for receiving a portion of a push-button 126 the major part of which is within the partition. The pushbutton is secured to a vertical slide 128 which is provided with spaced elongated slots 130 and 132 extending therethrough. The slide is freely received over pins 134 and 136 which extend through the slots 130 and 132 respectively and which are secured to the front wall 138 of the partition 116. A lever 140 is pivotally mounted at its medial portion on the pin 134 and with one of its ends 142 (FIG. 9) formed with an enlarged slot 144 through which freely extends a pin 146 secured to the slide 128. At the other end 147 of the lever 140 (FIG. 12) and pivotally connected thereto is a depending link 148 of twisted configuration and associated at its lower portion with a modified one-way spring clutch 150 of well-known construction and which will be described .in detail hereinafter.

A tension spring 152 secured to a pin 154 on the lever 140 and to a pin 156 on the slide 128 biases the lever 140 in a counterclockwise direction on the pin 134, as viewed in FIG. 12, thus urging the slide 128 to its upper position.

Secured to the left and right side walls 158 and 160 respectively of the partition 116 are small housing blocks 162 and 164 freely projecting through the slots 166 and 168 respectively of the side walls 98 and 100 of the magazine 96 and each containing an anti-friction bearing 170 (FIG. 13) for rotatably supporting the end portions of a shaft 172 extending through the right and left side walls 158 and 160 of the partition 116. Secured on the outer ends of the shaft 172 are spur gears 174 and 176 having hub portions 178 and 180 which extend partially into the interior of the partition 116 through suitable clearance apertures in the side walls 158 and 160. The gears 174 and 176 are in mesh respectively with racks 182 and 184 secured respectively to the right and left side walls 100 and 98 of the magazine 96'. Rotatably mounted on the end portions of the shaft 172 between the bearings 170 and the spur gears 174 and 176 are rollers 186 which bear on, and are adapted to ride along the lower horizontal edge portions 188 and 190 of the slots 166 and 168. As so arranged, the rollers 186 support the partition 116 at some clearance distance from the bottom wall 106 of the magazine 96 and at the same time maintain the proper pitch circle and pitch line relationship of the spur gears and racks to assure free movement of the spur gears without binding.

The partition 116 is maintained in a vertical position within the magazine 96 by an arrangement of gears and rollers similar to the one just described and which comprises a vertical shaft 192 (FIG. 12), journalled in brackets 194 and 196 secured to the side wall 160 of the partition. Secured on the end portions of the shaft 192 are spur gears 198 and 200 which extend through apertures 202 and 204 respectively in the side wall 160 to mesh respectively with racks 206 and 208 secured to the side wall 100 of the magazine 96. Rotatably mounted on the end portions of the shaft 192 are rollers 210 and 212 likewise extending through the apertures 202 and 204- and bearing on and adapted to ride along vertical flat surface portions 214 and 216 of the racks 206 and 208. The other side wall 158 of the partition carries a roller 215 mounted thereon by a bracket 217. During movement of the partition the roller rides against wall 98 to space that side of the partition away from the wall for frictionless movement of the partition.

The above-mentioned spring clutch 150 is mounted on the shaft 172 (FIGS. 12 and 13) and comprises an outer sleeve or barrel 218 secured to a bracket 2215 having upwardly extending flanges 222 secured as by screws 224 to the front and rear walls 138 and 226 of the partition 116. Freely received in one end of the barrel 218 is a collar 228 secured on the shaft 172. Also freely received in the opposite end of the barrel 218 is a sleeve 230 of a crank assembly, the latter comprising a crank arm 232 secured to a hub 234- fastened to sleeve 230, the crank assembly being freely mounted on the shaft 172 for rocking motion thereon. A left-hand helical spring 236 dissposed within the barrel 218 surrounds shank portions 238 and 240 of the collar 228 and sleeve 230 respectively, with one of its ends 241 anchored in a cross hole in the sleeve 230 and the other end 243 similarly anchored in a cross hole in the barrel 218. Secured to the extended portion of the crank arm 232 is a pin 242 extending freely through an elongated slot 244 (FIG. 12) in the lower end of twisted link 148. One end of a tension spring 246 is connected to the pin 242 and its other end is connected to a pin 248 secured to the lower end of the link 148.

With the mechanism of the partition 116 in the condition shown in FIG. 12, and when viewing along the axis of the shaft 172 from right to left in the figure, the shaft 172 can be turned in a clockwise direction so that the partition 116 can be moved forwardly-toward wall 102 simply by pushing it to the desired position. However, in this condition of the partition mechanism the shaft 172 cannot be turned in a counterclockwise direction since this motion would tighten the spring 236 and lock the collar 228 and shaft 172 against rotation. Thus when it is desired to retract the partition rearwardly from a forward position, the push-button 126 is depressed to raise the link 1 18 and rock the crank assembly whereby the spring 236 is sufficiently unwound to permit the collar 228 and shaft 172 to be freely rotated in either direction. Therefore it will be seen that the partition 116 can be moved forwardly in the magazine 96 simply by pushing it and can be pushed rearwardly therein by holding the pushbutton 126 depressed.

The outer face of the front wall 138 of the partition is formed with a pair of elongated depressions 250 (FIGS. 9 and 12) for receiving a pair of elongated feeler fingers 252 and 254 having free end portions 252 and 254 bent to prevent their ends from scraping the ledger sheets when the magazine is used in the stacking station. So that the fingers will rest fiush with the partition wall 138 at other times the bent ends project through apertures 256 and 258 in the wall 138 and into the interior of the partition 116. The opposite ends of the fingers extend through apertures 260 and 262 in the upper portion of the front wall 138 and are secured to a cross rod 264 journalled in brackets 266 and fixed to the inside face of the front wall 138. The feeler finger 252 is provided with a tab 268, as also seen in FIG. 16, adapted to extend through an aperture 270 in the front wall 138 of the partition 116 for rocking a switch actuating arm 272 against the biasing action of a torgue spring 274, the arm 272 being part of an L-shaped member 276 pivotally mounted on a pin 278 fixed to the right side wall 158 of the partition 116, as seen in FIG. 12.

Having now described most of the apparatus of this illustrative example, the remainder will be described in connection with the operation of the system in conjunction with the control instrumentalities, including the circuitry shown in FIG. 11.

In describing the operation, the apparatus will first be considered in a normal or non-operating condition in which the cradle 76 is in its lowermost, or loading position, as shown in FIG. 4 and as seen in solid lines in FIG. 8, and with the control circuitry in the condition as shown in FIG. 11.

A supply of ledger sheets 12less than its full capacity-is placed into the magazine 96a, before it is placed in the cradle 76 and the partition 116 slid forwardly until the end sheet of the stack is adjacent to and somewhat spaced from the front wall 102 of the magazine. The magazine is then placed on the loading platform 3 (FIGS. 1, 3 and 4) which is provided with a V-shaped track 282 having a surface 284 (FIG. 5) in line with the faces 286 of the projections 82 on the stop bar 84-, and having an opposite surface 288 (FIG. 4) in line with the forward member 74 of the cradle '76. It will be recalled that the projections 82 extend through the apertures in the rearward member 7 8 of the cradle 76 when the cradle is in its lowermost position.

The magazine 96a is then tilted into the track 282 and slid therealong into the cradle 76. In this position the magazine is supported by the projections 82 and the forward member 74 of the cradle (FIGS. 5 and 6). When the magazine is pushed into the cradle to the limit of its travel it will come against the stop flange 86 (FIG. 6) of the cradle and rock an arm 290 to close a switch 292 (see also FIG. 11) to partially condition the circuit for operation of the elevating mechanism.

A second magazine 96]) (FIG. 4) is then prepared for use in the stacking position by depressing its push-button 126 and sliding the partition 116 rearwardly until it abuts the rear wall 104 of the magazine, the rear wall 226 of the partition 116 being provided with an aperture, not shown, for receiving the anchor post 120 (FIGS. 6 and 10) secured to the rear wall 104 of the magazine 96b. In this position, the anchor post 120 projects into the interior of the partition 116 and partially extends through an elongated slot 294 (FIG. 12) in the slide 128. The push-button 126 is then released until the lower edge portion of the slot 294 is engaged in a recess 296 (FIG. 6) in the anchor post, thus to lock the partition against the rear wall of the magazine. The magazine is next placed on the loading platform 3 (FIG. 4) and tilted into a V-shaped track 296 with its rear wall 104 and partition 116 in an upward position, and then slid along the track into the machine until it is nested on stationary members 298 and 300 having portions in line with the track 296.

When the magazine reaches its limit. of travel it will come against a fixed positioning stop, not shown, and the housing block 162 (FIGS. 15 and 17) on the innermost side of the partition 116 will rock an arm 302 to close a switch 304 (see also FIG. 11) secured to a stationary member 306 of the machine thus to condition the circuit for operating a solenoid-actuated valve 308 (FIG. 8) for supplying vacuum to the feed wheel 14. Also, upon movement of the magazine 96b to the limit of its travel, the slot 310 (FIGS. 12 and 15) in wall 98 of the magazine and an aperture 312 in the side wall 158 of the partition 116 will pass freely over a lateral finger 314 secured to one arm 316 of a spring biased bell-crank lever 318 (see also FIG. 16) whose other arm 320 is in position for operating a full-stack switch 322 (see also FIG. 11), the lever 318 being pivotally mounted on a pin 324 fixed to the stationary member 306 of the machine, and the switch 322 being likewise fixed to the member 306.

In the operation of the system, the vacuum Wheel 14 and drive shaft 30 are rotating continuously. A pushbutton switch 326 (FIG. 11) is depressed to energize the coil R1 of a relay thereby to close the holding contacts R2 of the relay and move its transfer contact R3 from the normally closed contact R4 to the normally open contact R5 to energize solenoid 40 (FIG. 14). Energization of solenoid 40 causes the driving disc 62 to be magnetized and to magnetically attract and rotate the armature disc 64 thereby to impart rotation to the gears 68 and 26 and thus turn the elevating screw 24 (FIG. 8) to move the cradle 76 and magazine 96a angularly upwardly to the vacuum feed wheel 14.

As the cradle moves upwardly, the cam 85%, which in the lowermost position holds open the lower limit switch 90, -by-passes the switch and allows it to close. However, closing of switch 90 at this time has no efiiect on solenoid 42, as switch contacts R3 and R4 are open. When the top of the stack of sheets 12 reaches the feeding position which is preferably at a fixed feeding level, it will open the normally closed sensing switch 114 (FIGS. 8 and 11) thus to tie-energize the solenoid '40 and stop the upward movement of both the cradle 76 and magazine 96a. A sheet feed control switch 328 (FIG. 11) is then closed manually to energize the solenoid 330 of the valve 308, thus to operate the valve for supplying vacuum from a suitable source, not shown, to the wheel 14 through a hose 332 and for effecting feeding of sheets 12 individually and successively from the top of the stack.

When one or more of a predetermined number of sheets 12 have been separated from the stack by the feed wheel 14, the actuating arm 334 of the sensing switch 114 will be lowered accordingly to allow the switch 114 to close and again cause energization of the solenoid 40 for advancing the stack of sheets until the switch 114 again opens. This process will be repeated automatically until all of the sheets have been fed out of the magazine 96a. As the last or bottom sheet of the stack is fed out of the magazine, the actuating roller 336 of the sensing switch 114 will move into a clearance aperture 338 (FIG. in the front wall 138 of the partition 116 and the housing block 162 will rock a bell-crank lever 340 (FIG. 6) against the biasing action of a spring 342 to open an upper limit switch 344 (also see FIG. 11). Opening of switch 344 serves to de-energize the relay coil R1 to open the relay holding contacts R2 and return the transfer contact R3 from contact R5 to the contact R4, thereby deenergizing solenoid 40 and simultaneously energizing solenoid 42, switch 90 being closed. Energization of solenoid 42 will cause the driving disc 48 to magnetically attract and rotate the armature disc 56 thereby imparting rotation to gears 58 and 28 thus to rotate the elevating screw 24 for rapidly moving the cradle 76 and magazine 96a Y downwardly to the starting or loading position. It will be apparent from the gearing in FIG. 14 that the cradle and magazine will be moved downwardly at a faster rate than they are moved upwardly.

If during the sheet feeding operation it is desired to return the cradle 76 and magazine 96a prematurely to the starting position, a push-button switch 346 (FIG. 11) is depressed to affect the circuitry and operation in a manner similar to the opening of the upper limit switch 344.

Returning to FIG. 6, it is seen that the housing block 162 moves in a path intercepting arm 340 of upper limit switch 344 and when the last sheet is fed from the magazine the block acts to open the switch. Thus it is seen that since the block is carried by the movable partition 116, the length of upward travel of the cradle 76 in any given feeding operation will be governed by the height or thickness of the stack of sheets 12. In other words, stacks of various heights or thicknesses within the capacity of the magazine can be advanced to a sheet separation station with substantially no lost motion of the cradle and with a minimum expenditure of power and with less wear on the drive mechanism.

The downward movement of the cradle 76 and magazine 96a is stopped at the loading position when the cam 88 opens the lower limit switch 90 thereby to de-energize the solenoid 42. Due to the inertia of the apparatus and the tendency of the gear drive to override somewhat because of the flux change in solenoid 42 when it is deenergized, it would ordinarily be rather difficult to stop the magazine in a precise loading position relative to track 282 (FIG. 4) in the loading platform 3. To overcome this difliculty, the cam is so positioned that it will open the lower limit switch 9t} as the magazine is stopped by the projections 82 of the stop bar 84 while the cradle 76 coasts downwardly a short distance before it stops. Thus it is seen that the cradle 76 may be retracted rapidly and the magazine 96a accurately positioned relative to the track 282 in the loading platform and without any shock imposed on the drive mechanism.

As the sheets 12 are separated individually and successively from the stack in the supply magazine 96a, they are delivered into the primary feeding path 6 by the vacuum wheel 14 and advanced through the path and finally stacked in the receiving or stacking magazine 96b (FIG. 4) in a manner described in the aforementioned Bradshaw application and deposited into the stacking magazine in the same order and face position relative to the indentation or cut-out 112 in the front wall 102 of the stacking magazine 96b that they occupied when in the supply magazine 96a.

When the magazine is in the stacking position, feeler fingers 252 and 254 depend downwardly by gravity and are moved upwardly each time a sheet 12 is stacked in the magazine 9611. The fingers also serve to guide the leading edge of the ejected sheets downwardly to their stacked position in the magazine. When the magazine is full of cards or sheets 12, the fingers 252 and 254 will have been rocked upwardly so that the tab 263 on the finger 252, will extend through the aperture 270 (FIGS. 15 and 16) in the front wall 138 of the partition 116 thus to rock the actuating arm 272 against the finger 314 to open the full-stack switch 322 thereby to de-energize the solenoid 330 and shut off the vacuum to feeding wheel 14. Since no sheets will now be separated from the stack by the vacuum wheel, the sensing switch 114 will remain open and the elevating mechanism inoperative. A signalling device, not shown, may be included in the circuit to indicate to the operator that the stacking magazine 96b is full.

From the above description it will now be understood that the invention provides an improved sheet feeding system including apparatus for moving a stack or pile of sheet-like articles, such as ledger sheets, from a loading station to a feeding station, and control instrumentalities which among other functions are responsive to the separation of individual sheets from the stack by a feeding device for advancing the stack toward said device, and to the removal of the last sheet to return the apparatus to its loading station, while preventing the operation of the apparatus in the event the stack holding container, or magazine, is improperly positioned in the machine.

What is claimed is:

1. In a sheet feeding system, the combination comprising, a container for holding a supply of sheet items, means for removably supporting said container, means for advancing said support means and said container to a sheet separation station, means for driving said advancing means, electrically actuated coupling means for coupling the driving means to the advancing means, and means for controlling said electrically actuated coupling means, said last means including first and second normally open switches, said first switch being closed by said container when the latter is placed in said supporting means, and said coupling means being electrically actuated when both of said first and second switches are closed.

2. Sheet stack advancing apparatus comprising, a sheet stack container, means for removably supporting said container in the apparatus, means for advancing the supporting means and said container to a sheet separation station, means for driving said advancing means, electrically actuated means for coupling the driving means to the advancing means, electrical circuit means for controlling said electrically actuated means, first and second normally open switches in said circuit, said first switch being closed by said container when the latter is inserted into said supporting means and said coupling means being electrically actuated when both of said first and second switches are closed, and means in said circuit for rendering said coupling means inoperative when a stack of sheets in said container has been advanced therewith to a predetermined position and being responsive to the separation of a predetermined number of sheets from said stack for rendering the coupling means operative.

3. A sheet stack advancing apparatus as defined in claim 2 and including settable means for limiting the length of travel of said supporting means in the direction toward said sheet separation station in accordance with the height or thickness of a particular sheet stack in said container.

4. The combination comprising, a support for a stack of sheets, drive means for moving said support to and from a sheet feeding device, rotatable means for transmitting motion from the drive means to said support, said drive means comprising, a first driven gear for rotating the transmission means in one direction for moving the support forwardly to said sheet feeding device, a second driven gear coaxial with the first driven gear for rotating the transmission means in the opposite direction for moving said support in a reverse direction away from said sheet feeding device, first and second coaxial driving gears in mesh respectively with said first driven gear and said second driven gear, a drive shaft, and means to rotate the drive shaft, electrically actuated means for coupling said first driving gear to the drive shaft, electrically actuated means for coupling the second driving gear to the drive shaft, electrical circuit means for selectively controlling both of said electrically actuated means, a first switch in said circuit for rendering the electrically actuated means for the first driving gear inoperative when a stack of sheets on said support has been advanced therewith to a predetermined feeding position adjacent to the sheet feeding device and being responsive to the separation of a predetermined number of sheets from said stack for rendering said last mentioned electrically actuated means operative, a second switch in said circuit for rendering the electrically actuated means for the first driving gear inoperative and the electrically actuated means for the second driving gear operative for moving said support away from said sheet feeding device when a supply of sheets thereon has been exhausted, and means on said support for operating said second switch.

5. In a sheet feeding system, the combination comprising, a magazine for containing a stack of sheets, means for removably supporting the magazine, drive means for moving said supporting means and magazine to and from a sheet feeding device, rotatable means for transmitting motion from the drive means to said supporting means, said drive means comprising, a first driven gear for rotating the transmission means in one direction for moving the supporting means and magazine forwardly to said sheet feeding device, a second driven gear coaxial with the first driven gear for rotating the transmission means in the opposite direction for moving said supporting means and magazine in a reverse direction away from said sheet feeding device, first and second coaxial driving gears in mesh respectively with said first driven gear and said second driven gear, a drive shaft, and means to rotate the drive shaft, electrically actuated means for coupling said first driving gear to the drive shaft, electrically actuated means for coupling the second driving gear to the drive shaft, electrical circuit means for controlling operation of both of said electrically actuated means, a first normally open switch in said circuit and being closed by said magazine when the latter is placed in a predetermined position on said supporting means, a second switch in said circuit for rendering the electrically actuated means for the first driving gear inoperative when a stack of sheets in said magazine has been moved therewith to a predetermined feeding position adjacent to said sheet feeding device and being responsive to the separation of a predetermined number of sheets from said stack for rendering said last mentioned electrically actuated means operative, a third switch in said circuit for rendering the electrically actnated means for the first driving gear inoperative and the electrically actuated means for the second driving gear operative for moving said supporting means and magazine away from said sheet feeding device when a supply of sheets in said magazine has been exhausted, and means moving with said supporting means for operating said third switch.

6. A combination as defined in claim 5 characterized further by apparatus comprising, a loading facility having means for guiding the movement of a magazine into and out of said supporting means, and means in line with a surface of said guiding means for stopping said magazine independently of the supporting means as they are being moved in said reverse direction.

7. Apparatus for conveying a supply of sheets and the like articles comprising, a magazine for containing a stack of said sheets, means for removably supporting the magazine, drive means for moving said supporting means and magazine to and from a feeding station where sheets are removed one at a time from the stack, rotatable means for transmitting motion from the drive means to the supporting means, said drive means comprising, a first driven gear for rotating the transmission means in one direction for moving the supporting means and the magazine forwardly to said feeding station, a second driven gear coaxial with the first driven gear for rotating the transmission means in the opposite direction for moving said supporting means and said magazine in a reverse direction away from said feeding station, first and second coaxial driving gears in mesh respectively with said first driven gear and said second driven gear, a drive shaft, and means to rotate the drive shaft, a first electromagnetic clutch for coupling said first driving gear to the drive shaft, a second electromagnetic clutch for coupling the second driving gear to the drive shaft, electrical circuit means for energizing both of said clutches, a first normally open switch in said circuit and being closed by said magazine when the latter is placed in a predetenmined position on said supporting means, a second switch in said circuit and being operated by the stack of sheets at said feeding station for de-energizing said first electromagnetic clutch and being responsive to the removal of a predetermined number of sheets from the stack for re-energizing said first electromagnetic clutch, a third switch in said circuit for causing de-energization of said first electromag netic clutch and simultaneous energization of said second electromagnetic clutch for moving said supporting means and said magazine away from said feeding station when a supply of sheets in said magazine has been exhausted, means moving with said supporting means for operating said third switch, a magazine loading facility adjacent to the apparatus and having means for guiding a magazine into and out of the apparatus, and means in line with a surface of said guiding means for stopping said magazine while said supporting means is still in motion as they are being moved in said reverse direction.

8. In a sheet feeding system, apparatus for conveying a supply of sheet items one at a time from a loading station to a receiving or stacking station, said apparatus comprising a first magazine for containing the stack of said sheet items, means at said loading station for removably supporting said first magazine, a feeding device, drive means for moving said magazine supporting means and said magazine to and from said feeding device whereby said sheet items are removed from said magazine one at a time as the magazine moves in a direction toward said feeding device, said drive means comprising, rotatable means, means for translating rotation of said rotatable means to linear movement of said support means, a first driven gear for rotating said rotatable means in one direction for moving the support means and the magazine toward said feeding device, a second driven gear coaxial with said first driven gear for rotating the rotatable means in the opposite direction for moving said supporting means and said magazine in a reverse direction away from said feeding device for returning them to said loading station, first and second coaxial driving gears in mesh respectively with said first and second driven gears, a drive shaft, means to rotate said drive shaft, a first electromagnetic clutch for coupling said first driving gear to said drive shaft, and a second electromagnetic clutch for coupling the second driving gear to said drive shaft, means for selectively actuating said first and second electromagnetic clutches, a second magazine at said stacking station, means for transporting said sheet items one at a time, as they are removed by said feeding device, from said first magazine to said second magazine, means responsive to the insertion of said second magazine in said stacker station to enable operation of said feeding device to remove sheet items from said first magazine, and means adjacent said second magazine and responsive to the filling of said second magazine with said sheet items to disable the feeding evice when said second magazine is filled with such sheet items, and thus prevent feeding of further items from said first magazine even though items may still remain in said first magazine.

9. In a sheet feeding system, apparatus for conveying a supply of sheet items one at a time from a loading station to a receiving or stacking station, said apparatus comprising a first magazine for containing the stack of said sheet items, means at said loading station for removably sup porting said first magazine, a feeding device, drive means for moving said magazine supporting means and said magazine when said magazine is placed thereon to and from said feeding device whereby said sheet items are removed from said magazine one at a time as the magazine moves in a direction toward said feeding device, said drive means comprising, a rotatable screw shaft attached to said support means, means attached to said support and engaging said screw shaft for translating rotation of said shaft to linear movement of said support means, a first driven gear for rotating said screw shaft in one direction for moving the supporting means and the magazine toward said feeding device, a second driven gear coaxial with said first driven gear for rotating said screw shaft in the opposite direction for moving said supporting means and said magazine in a reverse direction away from said feeding device for returning them to said loading station, first and second coaxial driving gears in mesh respectively with said first and second driven gears, a drive shaft, means to rotate said drive shaft, a first electromagnetic clutch for coupling said first driving gear to said drive shaft, and a second electromagnetic clutch for coupling the second driving gear to said drive shaft, means for selectively actuating said first and second electromagnetic clutches, a second magazine at said stacking station, means for transporting said sheet items one at a time, as they are removed by said feeding device, from said first magazine to said second magazine, means responsive to the insertion of said second magazine in said stacker station to enable operation of said feeding device to remove sheet items from said first magazine, and means adjacent said second magazine and responsive to the filling of said second magazine with said sheet items to disable the feeding device when said second magazine is filled with such sheet items, and thus prevent feeding of further items from said first magazine even though items may still remain in said first magazine.

10. In a sheet feeding system, the combination comprising, a support for a stack of sheets, means for moving said support in forward or reverse direction to and from respectively a sheet separation station at a fixed feeding level, drive means, electrically actuated clutch means for coupling the drive means to said moving means for moving the stack support selectively in either the forward or the reverse direction, means for controlling said electrically actuated clutch means for forward movement of said stack support comprising first and second switching means, said first switching means being actuated by placement of a stack of sheets on said support and said clutch means being electrically actuated when both of said first and second switching means are actuated, and means carried by said support for effecting electrical actuation of said clutch means for moving said support in the reverse direction, said last means being bodily settable to different positions on said support for elfecting said electrical actuations, whereby the length of travel of said support in the forward direction may be varied in accordance with sheet stacks of various heights or thicknesses.

11. In a sheet feeding system, the combination comprising, a container for holding a supply of sheet items, means for removably supporting said container, means for advancing said support means and said container to a sheet separation station, means for driving said advancing means, electrically actuated coupling means for coupling the driving means to the advancing means, and means for controlling said electrically actuated coupling means, said last means comprising a first switching device and a second selectively operable switching device, said first switching device being actuated by the positioning movement of said container when the latter is placed in said supporting means, and said coupling means being electrically actuated when both of said first and second switching devices are actuated.

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